In today's′ radio communications networks, such as Wideband Code Division Multiple Access (WCDMA) networks, High Speed Packet Access (HSPA) has been introduced. HSPA uses High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA) and improves the performance of existing WCDMA networks. In HSUPA, work is ongoing to introduce multiple cell HSUPA, such as Dual-cell HSUPA. An objective with the work item is to specify Dual-cell HSUPA operation for the following scenario:                The dual carrier transmission only applies to HSUPA Uplink (UL) physical channels and Dedicated Physical Control Channel (DPCCH), the uplink DPCCH is used to carry the Dedicated Channel (DCH) transport channel        The carriers belong to the same Node-B, also known as radio base station, and are on adjacent carriers,        Operation with at least 2 carriers configured simultaneously in downlink        
In single carrier Enhanced Dedicated channel (E-DCH) operation, the Outer Loop Power Control (OLPC) parameters, such as Signal to Interference (SIR) target value is determined by a Network control node, e.g. the Serving Radio Network Controller (SRNC) and sent to a radio base station, called NodeB, alternatively, if the connection is over network interface lur, via the Drift Radio Network Controller (DRNC). The determination of the SIR target value uses the number of Hybrid automatic repeat request (HARQ) retransmissions that the SRNC receives in the header of an UL Data frame, a so called User Plane Protocol (UP Prot). The Node B then uses the SIR target value, for example, in an Inner Loop Power Control process (ILPC) between a User Equipment (UE) and the Node B. For example, in the uplink it is the ability of the transmitter of the UE to adjust its output power in accordance with one or more Transmit Power Control (TPC) commands received in the downlink from the Node B. The transmitter adjusts its output power in order to keep the received uplink Signal-to-Interference Ratio (SIR) at the given SIR target.
The E-DCH may use soft handover with one E-DCH serving cell plus one or more E-DCH non serving cells. In single carrier mode all cells are on the same carrier. With one carrier it is enough to have one OLPC process that may involve all the cells of the active set for E-DCH, it is not required to know in which cell the number of HARQ retransmissions has increased for proper setting of the SIR target in all cells of E-DCH active set.
When two or more carriers are introduced the assumption is that soft handover is used on each carrier, i.e. an active set of several cells may exist on each carrier, one cell per carrier is the serving E-DCH cell. Hence, a number of transport carriers will be used up to the SRNC to identify the number of HARQ retransmission with the carrier leading to a signaling that uses a lot of resources.
WO2004091114 discloses a system wherein number of ARQs is used when controlling transmission power of a user equipment. WO2006059172 discloses a system where channel quality is used when controlling transmission power of a user equipment. Document R1-090886 of 3GPP TSG RAN WG1 Meeting #56 in Athens, Greece, 09-3Feb. 2009 Titled Considerations on DC-HSUPA Operation discloses the use of TPC in DC-HSUPA.